Highly Efficient Near-Infrared Electrofluorescence from a Thermally Activated Delayed Fluorescence Molecule

Umamahesh Balijapalli, Ryo Nagata, Nishiki Yamada, Hajime Nakanotani, Masaki Tanaka, Anthony D'Aléo, Virginie Placide, Masashi Mamada, Youichi Tsuchiya, Chihaya Adachi

Research output: Contribution to journalArticlepeer-review

120 Citations (Scopus)


Near-IR organic light-emitting diodes (NIR-OLEDs) are potential light-sources for various sensing applications as OLEDs have unique features such as ultra-flexibility and low-cost fabrication. However, the low external electroluminescence (EL) quantum efficiency (EQE) of NIR-OLEDs is a critical obstacle for potential applications. Here, we demonstrate a highly efficient NIR emitter with thermally activated delayed fluorescence (TADF) and its application to NIR-OLEDs. The NIR-TADF emitter, TPA-PZTCN, has a high photoluminescence quantum yield of over 40 % with a peak wavelength at 729 nm even in a highly doped co-deposited film. The EL peak wavelength of the NIR-OLED is 734 nm with an EQE of 13.4 %, unprecedented among rare-metal-free NIR-OLEDs in this spectral range. TPA-PZTCN can sensitize a deeper NIR fluorophore to achieve a peak wavelength of approximately 900 nm, resulting in an EQE of over 1 % in a TADF-sensitized NIR-OLED with high operational device durability (LT95>600 h.).

Original languageEnglish
Pages (from-to)8477-8482
Number of pages6
JournalAngewandte Chemie - International Edition
Issue number15
Publication statusPublished - Apr 6 2021

All Science Journal Classification (ASJC) codes

  • Catalysis
  • General Chemistry


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